Simple method for rapid diagnosis of tuberculosis pleuritis: a statistical approach

Among the extrapulmonary presentations of tuberculosis, pleural tuberculosis is the second most frequent. Failure to diagnose and treat pleural tuberculosis can result in progressive disease with involvement of other organs in as many as 65% of patients. Conventional methods such as direct examination of pleural fluid, pleural fluid culture and pleural biopsy have proven to be insufficient for diagnoses of pleural tuberculosis. In this study, we examined a statistical method by combining the diagnostic efficiency of adenosine deaminase activity, pleural fluid protein, lactate dehydrogenase and cellular components in patients with tuberculous pleural effusions. Eighty eight patients over 12 years of age presenting with pleural effusions were included. A positive result by either three of the methods was considered to be indicative of a positive diagnosis of pleural tuberculosis. The determination of adenosine deaminase activity, lactate dehydrogenase levels, and lymphocyte to neutrophil ratio in the pleural fluid yielded a sensitivity of 100% for pleural tuberculosis. A patient was considered positive if any of the three tests was positive, with a specificity of 100%. A positive diagnosis was made when all three tests were positive. Similarly, these different approaches to the combination of pleural adenosine deaminase and lactate dehydrogenase result in sensitivity and specificity of 91.4% and 100% respectively.